ui: Rebuild all screens when the session epoch changes

Signing out and logging in as another account kept showing the
previous account's videos: the list ViewModels live in the activity
store and are keyed by destination only. A session epoch now
increments on logout and on each successful login; every ViewModel
key, grid scroll state and per-item focus map is keyed by it, so an
account switch starts from genuinely fresh data.

app/src/main/java/net/jeena/jtubetv/ui/AppViewModel.kt

@@ -19,6 +19,13 @@ class AppViewModel(private val repository: PeerTubeRepository = AppGraph.reposit
     private val _sessionState = MutableStateFlow<SessionState>(SessionState.Loading)
     val sessionState: StateFlow<SessionState> = _sessionState
 
+    /**
+     * Bumped on every logout and successful login: all list ViewModels and saved
+     * UI state are keyed by it, so switching accounts never shows the previous
+     * account's cached content.
+     */
+    val sessionEpoch = MutableStateFlow(0)
+
     val loginError = MutableStateFlow<String?>(null)
     val loggingIn = MutableStateFlow(false)
 
@@ -35,6 +42,7 @@ class AppViewModel(private val repository: PeerTubeRepository = AppGraph.reposit
             loggingIn.value = false 
             if (result.isSuccess) {
                 _sessionState.value = SessionState.Ready
+                sessionEpoch.value += 1
             } else {
                 loginError.value = if (result.exceptionOrNull() is PeerTubeRepository.BadCredentialsException) {
                     "Invalid credentials"
@@ -60,5 +68,6 @@ class AppViewModel(private val repository: PeerTubeRepository = AppGraph.reposit
     fun logout() {
         repository.signOut()
         _sessionState.value = SessionState.NeedsSetup
+        sessionEpoch.value += 1
     }
 }

app/src/main/java/net/jeena/jtubetv/ui/screens/ChannelsScreen.kt

@@ -65,7 +65,8 @@ class ChannelsViewModel(private val store: TokenStore) : PagedListViewModel<Vide
 @Composable
 fun ChannelsScreen(
     onOpenChannel: (handle: String) -> Unit,
-    viewModel: ChannelsViewModel = viewModel(factory = ChannelsViewModel.factory),
+    epoch: Int = 0,
+    viewModel: ChannelsViewModel = viewModel(key = "channels$epoch", factory = ChannelsViewModel.factory),
 ) {
     LaunchedEffect(Unit) { viewModel.loadMore(force = true) }
 

app/src/main/java/net/jeena/jtubetv/ui/screens/HomeRows.kt

@@ -124,7 +124,8 @@ class RecentVideosViewModel(private val repository: PeerTubeRepository) : PagedL
 fun HomeRowsScreen(
     onOpenVideo: (VideoDto) -> Unit,
     restoreToken: Int = 0,
-    viewModel: HomeRowsViewModel = viewModel(factory = HomeRowsViewModel.factory),
+    epoch: Int = 0,
+    viewModel: HomeRowsViewModel = viewModel(key = "home$epoch", factory = HomeRowsViewModel.factory),
 ) {
     LaunchedEffect(Unit) { viewModel.load() }
     LaunchedEffect(restoreToken) { if (restoreToken > 0) viewModel.refresh() }

app/src/main/java/net/jeena/jtubetv/ui/screens/HomeScreen.kt

@@ -15,6 +15,7 @@ import androidx.compose.material.icons.filled.VideoLibrary
 import androidx.compose.material.icons.filled.PersonalVideo
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
@@ -47,6 +48,7 @@ enum class Destination(val title: String) {
  *  focused card survive BACK (couch users don't want to re-navigate from the top). */
 @Composable
 fun HomeScreen(viewModel: AppViewModel = androidx.lifecycle.viewmodel.compose.viewModel()) {
+    val epoch by viewModel.sessionEpoch.collectAsState()
     var destination by rememberSaveable { mutableStateOf(Destination.Home) }
     var channelDetails by rememberSaveable { mutableStateOf<String?>(null) } // handle
     var playingVideo by rememberSaveable { mutableStateOf<String?>(null) }  // shortUUID
@@ -64,6 +66,7 @@ fun HomeScreen(viewModel: AppViewModel = androidx.lifecycle.viewmodel.compose.vi
     }
 
     Box(modifier = Modifier.fillMaxSize()) {
+        androidx.compose.runtime.key(epoch) {
         if (destination == Destination.Channels && channelDetails != null) {
             androidx.compose.foundation.layout.Box(
                 modifier = Modifier
@@ -75,6 +78,7 @@ fun HomeScreen(viewModel: AppViewModel = androidx.lifecycle.viewmodel.compose.vi
                     source = ListSource.Channel(channelDetails!!, channelDetails!!),
                     onOpenVideo = { playingVideo = it.shortUUID },
                     restoreToken = restoreToken,
+                    epoch = epoch,
                 )
             }
         } else {
@@ -133,33 +137,41 @@ fun HomeScreen(viewModel: AppViewModel = androidx.lifecycle.viewmodel.compose.vi
                 ) {
                 when (destination) {
                     Destination.Home ->
-                        HomeRowsScreen(onOpenVideo = { playingVideo = it.shortUUID })
+                        HomeRowsScreen(
+                            onOpenVideo = { playingVideo = it.shortUUID },
+                            epoch = epoch,
+                        )
                     Destination.MyVideos ->
                         VideoListScreen(
                             source = ListSource.MyVideos,
                             onOpenVideo = { playingVideo = it.shortUUID },
                             restoreToken = restoreToken,
+                            epoch = epoch,
                         )
                     Destination.Channels -> ChannelsScreen(
                         onOpenChannel = { handle -> channelDetails = handle },
+                        epoch = epoch,
                     )
                     Destination.Search ->
                         VideoListScreen(
                             source = ListSource.Search,
                             onOpenVideo = { playingVideo = it.shortUUID },
                             restoreToken = restoreToken,
+                            epoch = epoch,
                         )
                     Destination.Subscriptions ->
                         VideoListScreen(
                             source = ListSource.Subscriptions,
                             onOpenVideo = { playingVideo = it.shortUUID },
                             restoreToken = restoreToken,
+                            epoch = epoch,
                         )
                     Destination.History ->
                         VideoListScreen(
                             source = ListSource.History,
                             onOpenVideo = { playingVideo = it.shortUUID },
                             restoreToken = restoreToken,
+                            epoch = epoch,
                         )
                 }
                 }
@@ -174,6 +186,7 @@ fun HomeScreen(viewModel: AppViewModel = androidx.lifecycle.viewmodel.compose.vi
         }
         }
     }
+}
 
 private fun Destination.icon(): androidx.compose.ui.graphics.vector.ImageVector =
     when (this) {

app/src/main/java/net/jeena/jtubetv/ui/screens/SetupScreen.kt

@@ -16,9 +16,12 @@ import androidx.compose.runtime.Composable
 import androidx.compose.runtime.State
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
 import androidx.compose.runtime.saveable.rememberSaveable
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.focus.FocusRequester
+import androidx.compose.ui.focus.focusRequester
 import androidx.compose.ui.input.key.Key
 import androidx.compose.ui.input.key.key
 import androidx.compose.ui.input.key.onPreviewKeyEvent
@@ -41,7 +44,12 @@ fun SetupScreen(
     val password = rememberSaveable { mutableStateOf("") }
     val showPassword = rememberSaveable { mutableStateOf(false) }
     val clipboard = LocalClipboardManager.current
-    val focusManager = androidx.compose.ui.platform.LocalFocusManager.current
+    // Deterministic D-pad chain: DOWN from URL goes to Username, not Password
+    // (geometric focus search misfired on device).
+    val urlFocus = remember { FocusRequester() }
+    val userFocus = remember { FocusRequester() }
+    val passFocus = remember { FocusRequester() }
+    val signInFocus = remember { FocusRequester() }
     val busy = loggingIn.collectAsState()
     val message = error.collectAsState()
     val localError = rememberSaveable { mutableStateOf<String?>(null) }
@@ -67,11 +75,17 @@ fun SetupScreen(
                 onValueChange = { url.value = it },
                 label = { Text("PeerTube instance URL") },
                 singleLine = true,
+                keyboardOptions = androidx.compose.foundation.text.KeyboardOptions(
+                    imeAction = androidx.compose.ui.text.input.ImeAction.Next,
+                ),
+                keyboardActions = androidx.compose.foundation.text.KeyboardActions(
+                    onNext = { userFocus.requestFocus() },
+                ),
                 modifier = Modifier
+                    .focusRequester(urlFocus)
                     .onPreviewKeyEvent { ke ->
                         when (ke.key) {
-                            Key.DirectionDown -> { focusManager.moveFocus(androidx.compose.ui.focus.FocusDirection.Down); true }
+                            Key.DirectionDown -> { userFocus.requestFocus(); true }
-                            Key.DirectionUp -> { focusManager.moveFocus(androidx.compose.ui.focus.FocusDirection.Up); true }
                             else -> false
                         }
                     }
@@ -83,11 +97,18 @@ fun SetupScreen(
                 onValueChange = { username.value = it },
                 label = { Text("Username") },
                 singleLine = true,
+                keyboardOptions = androidx.compose.foundation.text.KeyboardOptions(
+                    imeAction = androidx.compose.ui.text.input.ImeAction.Next,
+                ),
+                keyboardActions = androidx.compose.foundation.text.KeyboardActions(
+                    onNext = { passFocus.requestFocus() },
+                ),
                 modifier = Modifier
+                    .focusRequester(userFocus)
                     .onPreviewKeyEvent { ke ->
                         when (ke.key) {
-                            Key.DirectionDown -> { focusManager.moveFocus(androidx.compose.ui.focus.FocusDirection.Down); true }
+                            Key.DirectionDown -> { passFocus.requestFocus(); true }
-                            Key.DirectionUp -> { focusManager.moveFocus(androidx.compose.ui.focus.FocusDirection.Up); true }
+                            Key.DirectionUp -> { urlFocus.requestFocus(); true }
                             else -> false
                         }
                     }
@@ -102,11 +123,14 @@ fun SetupScreen(
                 visualTransformation =
                     if (showPassword.value) androidx.compose.ui.text.input.VisualTransformation.None
                     else androidx.compose.ui.text.input.PasswordVisualTransformation(),
+                keyboardOptions = androidx.compose.foundation.text.KeyboardOptions(
+                    imeAction = androidx.compose.ui.text.input.ImeAction.Done,
+                ),
                 modifier = Modifier
+                    .focusRequester(passFocus)
                     .onPreviewKeyEvent { ke ->
                         when (ke.key) {
-                            Key.DirectionDown -> { focusManager.moveFocus(androidx.compose.ui.focus.FocusDirection.Down); true }
+                            Key.DirectionUp -> { userFocus.requestFocus(); true }
-                            Key.DirectionUp -> { focusManager.moveFocus(androidx.compose.ui.focus.FocusDirection.Up); true }
                             else -> false
                         }
                     }

app/src/main/java/net/jeena/jtubetv/ui/screens/list/VideoListScreen.kt

@@ -42,20 +42,21 @@ fun VideoListScreen(
     source: ListSource,
     onOpenVideo: (VideoDto) -> Unit,
     restoreToken: Int = 0,
+    epoch: Int = 0,
     viewModel: VideoListViewModel = viewModel(
-        key = sourceKey(source),
+        key = "v$epoch:" + sourceKey(source),
         factory = VideoListViewModel.factory(source),
     ),
 ) {
     val items = viewModel.items
     // per-item focus requesters so BACK from the player can refocus the opened card
-    val requesters = remember(items.size) {
+    val requesters = androidx.compose.runtime.remember(items.size, epoch) {
         androidx.compose.runtime.mutableStateMapOf<Int, FocusRequester>()
     }
     // Pull initial focus out of the sidebar rail and into the content grid.
     val initialFocus = remember { FocusRequester() }
     // Which card was opened last — re-focus it when playback ends (UX report BUG-3).
-    var lastOpenedIndex by androidx.compose.runtime.saveable.rememberSaveable { mutableStateOf(-1) }
+    var lastOpenedIndex by androidx.compose.runtime.saveable.rememberSaveable(epoch) { mutableStateOf(-1) }
     LaunchedEffect(items.isNotEmpty(), source) {
         if (items.isNotEmpty()) runCatching { initialFocus.requestFocus() }
     }
@@ -72,7 +73,8 @@ fun VideoListScreen(
     }
     // Scroll position survives destination switches (per source), not just player exits.
     val gridState = androidx.compose.runtime.saveable.rememberSaveable(
-        key = sourceKey(source), saver = androidx.compose.foundation.lazy.grid.LazyGridState.Saver,
+        inputs = arrayOf(epoch),
+        key = "g$epoch:" + sourceKey(source), saver = androidx.compose.foundation.lazy.grid.LazyGridState.Saver,
     ) { androidx.compose.foundation.lazy.grid.LazyGridState() }
 
     when (source) {